Respirometer



Nov. 25, 1941. c. M. HAMMOND RESPIROMETER Filed Nov. 2, 1938 5 Sheets-a'heet l Nov. 25, 1941. c. M. HAMMOND 2,263,844

RESPQIROMETER Filed Nov. 2, 1958 w 5 Sheets-Sheet 2 Ndv. 25,1941. c. M. HAMMOND RESPIROMETER 5 Sheets-Sheet 5 Filed Nov. 2, 1938 .iM /v ale 5 Mew/mm Nov, 25, 1941. c. M. HAMMOND RESPIROMETER Filed Nov. 2, 1938 5 Sheets-Sheet 4 Mae/van airman Nov. 25, 1941. C, M, HAMMOND 2,263,844

RESPIROMETER Filed Nov. 2, 1938 5 Sheets-Sheet 5 www 95' 3- was as 39 e44 ilk/1 9;; 1-

JZ //Y/ /6 Warsaw/ me Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE Charles m. Hammond, Memphis, 'reim. Application November z, 1938, serial No. 233,334

8 Claims. (01. 128-30) This invention relates to devices for inducing respiration, particularly in the human body and especially to devices of this kind which mechanically induce and maintain respiration over a more or less extended period of time.

It further relates to a device of this kind in which the head and torso are separately but concurrently and reversely acted on. a partial vacuum and air pressure being alternately set up around the head whereby to artifically induce respiration and concurrently and reversely air pressure and partial vacuum are alternately set up around the torso whereby to assist in the establishment of the lung action.

The invention further relates to a device of this kind in which oxygen may be substituted in whole or in part for the air around the head and in which the air, or oxygen so substituted, may be cooled or heated as necessity may indicate.

The objects of the invention are:

To provide a casing which will completely enclose both the head and the body of the patient in separate compartments, and which may be hermetically sealed.

To provide as a portion of suchcasing a sectional top which may be fully opened to allow placing of the patient within the casing, and his or her subsequent removal therefrom.

To provide means for hermetically sealing the sections of the top together and of the top to the remaining portion of the casing.

To provide a sectional diaphragm cooperating with said casing including one of the sections of said top.

To provide means for sealing the diaphragm around the neck of the patient and the parts the diaphragm together.

To provide means for alternately exhausting air from the head: portion of th casing and establishing air pressure in such casing.

' To provide means for alternately establishing air pressure in the body portion of said casing and exhausting air therefrom.

To provide means for synchronizing the action of such exhaust and pressure means whereby reduction of air pressure in the head portion of the casing is concurrent with increase of air pressure in the body portion of the casing, and following such action increase of air pressure in th head portion of the casing is concurrent with reduction of air pressure in the body portion of the casing, such actions being serially repeated.

To provide means whereby air delivered to the casing may be heated or cooled. v

To provide means whereby oxygen maybe substituted in whole or in part/for the air delivered to the head portion of the casing; and

To provide indicating means whereby the pres sures and vacuums set up in the device are visually shown.

The means by which the foregoing and other objects are accomplished, and the manner of their accomplishment will readily be understood from the following specification on reference to the accompanying drawings, in which:

Fig. 1 is a side elevation of the respirometer.

Fig. 2 is a sectional side elevation taken on the broken line 11-11 of Fig. 6.

Figs. 3 and 4 are transverse sectional elevations taken respectively on the lines III-III and IVIV of Fig. 1.

Fig. 5 is a fragmentary section taken on the line V-V of Fig. 3 showing an enlarged detail of the sealing structures used.

Fig. 6 is a sectional plan taken on the line VI-VI of P18. 1.

Fig. 7 is a fragmentary longitudinal'section taken on the line VII-VII of F18. 3; and

Fig. 8 a fragmentary elevation looking in the direction of the arrow 0 of Fig. 7.

Fig. 9 is a fragmentary section corresponding to Fig. 4 showing a current control belt adapted to encircle the body of the patient.

Fig. 10 is a fragmentary diagrammatic sketch of the switch shown in Fig. 9; and

Fig. 11 is a diagrammatic sketch of the mechanism and wiring controlled by the belt of Fig. 9.

Referring now to the drawings in which the various parts are indicated by numerals:

Th respirometer includes an elongated casing to receive the patient, this casing including a substantially rectangular base portion iii to which is hingedly secured. a torso cover II, a diaphragm cover I! and a head cover l3. Suitable hinges ll secure the end of the head cover to the base section i0, and latches l5, l6v secure the head cover to the diaphragm cover l2, and

to the base portion Ill respectively, when the head cover is closed. Similar hinges ll along one longitudinal edge of the torso covers II and diaphragms I2, hinge these covers to the base portion l0 and latches l8 and I9 complete the attachment of these covers respectively when they are closed. v

The base portion I0 is provided around its entir periphery with a member 20 which forms, with the upper edges of the side and end walls. a groove adapted to receive a resilient sealing strip 2| against which the various top sections are clamped by the hinge and latch actions.

22, 23 are upper and lower portions of a diaphragm which divides the casing into head and torso chambers 24, 25 respectively. The upper portion of the diaphragm is integrally secured to the diaphragm cover I2 and the lower portion of the diaphragm to the base III. An opening 21 is made through the diaphragm, part of this opening being in the upper and part in the lower portion, which opening is adapted to receive the neck oi a patient. 28 is a collar of resilient material which is adapted to surround the neck of the patient in an air-tight manner. This collar is cut in two along one side so that it may be placed around the patients neck and is provided with a zipper 23 or other means whereby it may be secured together and the secured edges sealed. A portion 30 also of the collar, preferably that which underlies the back of the patients neck is of tubular form and is provided with a suitable inlet tube 3| and a closure valve 32 whereby it may be inflated and caused to conform closely to the contour of the neck surface. The base of the collar has a flange 33 extending laterally outward that seats against the diaphragm 22, 23. This flange is, like collar portion, cut in two at one side so that both collar portion and base portion may be open to receive the patients neck and the lower left is permanently held against the diaphragm section 23 by an arcuate ring section 34 secured as by screws 35, the other half being adapted to be secured to the diaphragm section 22 by a complementary ring portion 36 which is secured in place by camming members 31. The two sections 22, 23 of the diaphragm are provided along their meeting edges with sealing strips 38 (Fig.

48 is a sealing strip forming a Joint between the head cover I3 and the diaphragm cover I2 along the periphery of the upper diaphragm 22. H is a similar sealing strip which seals the joint between the torso cover II and the diaphragm cover I2. 42 indicates a pillow and 43 a mattress.

Disposed below the casing thus formed is an air compressing mechanism. This mechanism comprises two double acting cylinders 53, 5|, each cylinder having a piston therein, the piston 52 of the cylinder 50 being shown. 53, 54 are the piston rods of the cylinders 50, 5| respectively. -These piston rods are reciprocated in unison as by crank pins 55, 56 respectively, which pins are carried by crank discs 51, 58, these discs being rigidly secured on a joint shaft 53 which is journalled in suitably supported bearings 58. 6|, 62 are slotted crossheads carried by the piston rods 53, 54 respectively and in which the pins 55, 55 are respectively operatively disposed. Extensions 54'-A, 55--A of the piston rods are supported and reciprocate in guide bearings 63.

Mounted on the shaft 53 between the bearings 60, is a pulley 64, here shown as a grooved pulley having two steps, which pulley is driven from a complementary pulley 65 through a belt 65, the belt 56 being shiftable from one set of grooves or steps of the two pulleys to the other set to vary operating speeds. 61 is a variable speed motor which is connected through an usual speed reduction mechanism 58 to the pulley 65.

13, H are complementary discs of a magnetic clutch such as may be bought in the open market, this clutch having one disc 18 secured to the shaft 53 and the other disc 1| to the pulley 64. The clutch has the usual collecting rings 12, 13 and contact brushes 14, 15 through which current is delivered to the clutch, no attempt having been made to show the insulation or other detail of these parts.

In Fig. 11, is a source of current, here indicated as a battery, which has one lead 8I to the clutch contact brush 14, and the other lead 82 to a control switch 83, by which it may be cut oil should it be so desired. The switch is ordinarily closed through the pole 84 and leads 85, 85 directly to the opposite brush 15 of the clutch to establish operative engagement of the clutch discs 13, 1|. Optionally the switch 83 may be shifted to the pole 38 and through lead 3| to a contact member 32. 33 is a complementary contact member and 34 a lead from this complementary contact member to the lead 86.

35 is a belt adapted to be placed around and partially encircle the body of the patient in such position as to respond to the breathing of the patient, the belt being provided with securing means 36 through which it may be adjusted to the individual patient. The ends of this belt are spaced apart and have blocks 31, 38 of insulating material, such as hard rubber or Bakelite, secured respectively thereto, the blocks being urged together as by tension springs 33.

The contact members 32, 33 are preferably substantially of U shape with one short leg each, the longer legs being respectively secured to the blocks 31, 38. These contact members extend into over-lapping relation, with their shorter legs I03, I||| making sliding contact as breath enters the patients lungs and expands the body, and remaining in such contact as breath is expelled from the lungs and the body responsively collapses, this contact continuing almost to the completion of breath exhalation, butat this point the ends of the contact members separate and the contact is broken. I02, I83 are blocks of insulating material secured respectively to the blocks 31, 38 which insure separation of the. short leg of one U from the long leg of the other U at such time, such insulation obviously being extendable along the entire length of the U leg if so desired.

The inner ends of the cylinders 50, 5| are connected by passageways 3, III and a joint passageway II2 with the interior of the torso chamber of the device, these passageways being unobstructedly open. At its outer end the cylinder 53 has an intake passageway II5 which leads from the head end of the casing into the cylinder. This flow from the casing is through a valve 6 which opens against pressure of a spring H1 and is reseated by such spring to prevent return flow to the casing. H8 is a discharge passageway from the cylinder 50, flow through this passageway from the cylinder being permitted by a valve I I3 which is held seated by a spring I23, this valve preventing return flow through the passageway to the cylinder. The passageway I|8 discharges through a chamber I2I having a perforate bottom, in which chambers a chemical I22, such as soda-lime, adapted to absorb carbon dioxide is contained, and through which chemical the air discharged from the cylinder must pass. From the chamber I2I a passageway I23 continues. This passageway has a branch I24 which leads to an inflatable bag I25 adapted to receive and temporarily store the discharge from the cylinder 50. The passageway also has a second branch I26 which leads into the cylinder I21 is a valve, held seated by a spring I28, which permits discharge of air through the passageway I26 into the cylinder 5|, but prevents return flow therefrom. The stem I29 of the valve I21 extends through the wall of the passageway I26 and is controlled additionally in a manner to be hereinafter described. I30 is a discharge passageway from the outer end of the cylinder 5|, this passageway discharging through an opening I3I into the head chamber of the casing. I32 is a valve normally held seated by a spring I33 to close the opening I3I, this valve opening against the spring action to permit discharge from the passageway I30.

I35 is a passageway leading from the torso chamber to an expandable bag I36, flow to this bag being controlled by a valve I31, normally held closed by a spring I38, this valve seating in the direction of flow from the torso chamber so that it must necessarily be mechanically raised to permit such flow.

Mounted on and secured to the shaft 59 is a cam I49 having oppositely disposed lift portions I4I, I42, both having abrupt rises, which respectively engage oppositely disposed rods I43, I44 respectively. The rod I43 is connected through an arm I45 to a rod I46 which extends beyond the cylinders and contacts one end of an arm I41 pivotally supported as by a bracket-carriedpin I48. The opposite end I49 of the arm engages the stem I29 of the valve I21, engagement being made through a threaded extension I50, which extension may be adjusted outward to increase the throw of the valve, or inward, to decrease same even to the extent of entirely cancelling opening movement.

The rod I44 extends oppositely to a pin connection with a bell crank lever I52 through which thrust of the rod I44 is transmitted through an adjustable, threaded member I53 to the stem I54 of valve I31, adjustment of the threaded member here again increasing the throw of the valve, or decreasing the same to the point of cut ofi.

I69, I6I are caps which may be removed to uncover openings into the head chamber, and I62 a similar cap closing an opening into the torso chamber. These caps when removed permitting the insertion of tubes for introducing oxygen into the head chamber or samples of the air content of that chamber either singly or concurrently and for introducing tubes into the torso chamber as for blood transfusions or other intravenous injections.

I65, I66 are windows through which the head and body of a patient may be observed. I61, I68 are manometers. ably provided with hinges I19, and latches I1I so that they be opened when and if necessary.

In using the device the latches I5 and I6 are released and the head cover I3 is opened about the hinges I4. The latches I8 are released and the torso cover II is turned back about the hinges II; the latches I9 are released and the diaphragm cover I2 is turned back about its hinges,-this secondary torso cover carrying with it the attached upper half 25 of the diaphragm and leaving the mattress 43 and the pillow 42 fully accessible and the collar 28 similarly accessible. The closure 29 is released and the .upper half of the collar 28 turned back.

The patient may then be placed in the apparatus and the collar closed and fastened. The

Windows I65, I66 are prefer-.

upper portion of the collar so closed comes around the patients chin and along the opposite sides -of the lower jaw, the inflatable portion 30 which has previously been collapsed underlying the back of the patients neck. Air is introduced through the valve 32 causing the collar to conform itself closely to and seal around the neck, and drawing the upper portion into sealing contact with the jaw and chin. The secondary torso cover I2 is closed and latched, the upper half 25 of the diaphragm seating on the sealing strips 38. The ring section 36 is placed against the upper half of the collar flange 33 and is clamped thereagainst by the camming members 31 to complete the sealing of the diaphragm separating the head and body sections of the apparatus. The main torso cover I2 and the head cover II are then closed and secured by their respective latches and the apparatus is ready for use.

The clutch control switch 83 is shifted to neutral position, disconnecting the clutch discs 19, 1| and current is turned on to the motor 61. When the motor 61 has reached running speed the clutch control switch 83 is shifted, preferably to the pole 98, and through the contacts 92, 93, to energize the clutch and start up the air pumping mechanism. Before throwing in the clutch the patients breathing is observed through the windows I65, I86 and the position of the pump pistons and their direction of movement is checked in order to start the operation of this mechanism as nearly in synchronism with the patients breathing as possible, except that it is desirable to so start the mechanism that "the operation will slightly lead the corresponding breathing of the patient. With the clutch cut in, the mechanism starts functioning approximately in step with the patients breathing completing such portion of the inhalation and exhalation breathing cycle as may remain, the mechanism starting the inhalation portion of the next cycle, slightly before exhalation i completed by the patient. Unless, however, the-patients breathing instantaneously responds to this lead of the mechanism, completion of exhalation by the patient disconnects the contact 92, 93 and cuts off the magnetic clutch 19, 1I until such time as the patients breathing again closes the contacts 92, 93 and re-establishes clutch action and the mechanical cycle.

Should the mechanism speed be greater than the patients breathing speed the same cut-out action will occur at the end of this breathing cycle, and each succeeding breathing cycle until regulation of the motor speed is made to synchronize the apparatus speed with the patients breathing cycle. If the mechanism speed is slower than the patients breathing the samecondltion will occur except that cut-out of the clutch will throw the apparatus still further out of step and in such case it is advisable to cut off the clutch entirely and speed up the motor to a speed approximately slightly greater than that of the patients breathing and again cut in the clutch through the control contacts 92, 93 and regulate as before. When the mechanism has been synchronized with the patients breathing, the switch 83 preferably is shifted to the pole 84 and steady halation periods, but primarily by lengthening the inhalation period, slowing the patient's breathing to a more desirable rate.

During operation of the mechanism, as the piston in cylinder 50, is drawn away from the outer head of the cylinder, air is drawn from the head section of the casing through the passageway I I5 into the cylinder, this action by reducing the pressure in the head chamber assisting the patient in exhaling. The air thus drawn into the cylinder 50 is forced out of the cylinder through the passageway H8 and through the soda-lime l2| in the chamber H9, and through passageways I23, I24 into the bag I25 .,in which it is temporarily stored. Return of air to the head chamber during this cycle is prevented by the valve H6, and return of: air from the passageway H8 to the cylinder by the valve 9.

The piston in cylinder 5| moves concurrently with the above described movement of piston 52. On the instroke this piston draws in air from the bag I25 through passageways I24, I26 past the non-return valve I21 into the cylinder, and on the out stroke delivers this air through passageway I30 past non-return valve I32 into the head section, from which it is withdrawn into cylinder 50 as described above duringthe next succeeding cycle.

As the pistons in cylinders ill and SI move inward, as above described, they force air through the passageways IIII, III, II2 into the torso section of the casing,and on the return stroke withdraw the same amount of air therefrom, thus building up pressure in the torso chamber as pressure is reduced in the head chamber and reducing this pressure as pressure is increased in the head chamber.

As the pistons approach the inner end of the stroke the lift portion I of the cam I40 rather abruptly shifts the rod I43 and through the arm I45, rod I46 and arm I4II49, opens the valve I21 establishing connection to the bag I25 permitting equalization of the pressures therebetween. Concurrently the lift portion I42 of the cam, acting similarly through the rod I44, and bell crank lever I52, opens the valve I31 and permits equalization of the pressure in the torso chamber with the bag I36. The lift portions I4I, I42 of the cam, being 180 degrees apart, accomplish the identical valve openings at the opposite ends of the piston strokes so that at the completion of both the exhaust and pressure strokes in the head chamber and the concurrent completion of the pressure and exhaust strokes in the torso chamber, the pressures in these chambers are re-established substantially at atmospheric pressure as in normal breathing.

Should it be found desirable, one of the caps IGII or ISI may be removed, and usual and well known apparatus for supplying oxygen may be connected through the opening left by the removal of the cap to enrich the air being supplied to the patient, such oxygen apparatus forming no part of the present invention, not being here shown. The outer cap may be removed and air withdrawn from the head chamber for testing CO: and oxygen content, or other purposes. Either of the caps may be removed for either of the above purposes, two however are preferably supplied as shown in order that both oxygen supply and test connection may be made at the same time should this be desirable. The cap I63 on the torso section may from time to time be removed and tubes introduced, as for intravenous feeding, blood transfusion or the like. In

such cases the body cover II is temporarily opened while connection of the needle into the patients vein is being made, and after such connection, closed during the transfusion or intravenous i'eedins.

Observation of the patient within the casing may be made through the windows I04, I" provided in the head and torso covers respectively.

I claim:

1. In a respirometer including a casing divided into complementary sealed head and body chambers, means for alternately increasing and reducing pressure in one ,.of said chambers, and synchronously alternately reducing and increasing pressure in the other thereof.

2. In a respirometer including a scalable casing divided into complementary head and body chambers, means for alternately increasing and reducing pressure above and below atmospheric pressure in one of said chambers and synchronously alternately similarly reducing and increasing pressure in the other thereof, and synchronized means for re-establishing atmospheric pressure at the completion of each cycle.

3. In a respirometer comprising a scalable casing divided into complementary head and body chambers, means for alternately increasing and reducing pressure above and below atmospheric pressure in one of said chambers and synchronously alternately similarly reducing and increasing pressure in the other thereof, and synchronized means for re-establishing atmospheric pressure at each pressure reversal.

4. In a respirometer comprising a casing divided into complementary chambers, adapted respectively to enclose the head and body of a patient, means for alternately increasing and reducing pressure in one of said chambers, and synchronously alternately reducing and increasing pressure in the other thereof, said means including an electric motor drive, a magnetic clutch for transmitting power therefrom, and clutch control means including a source of electric current, a circuit therefrom to said clutch,

said circuit including a switch; and means responsive to breathing of said patient for opening and reclosing said switch at a predetermined point in the breathing of said patient.

5. In a respirometer comprising a casing, adapted to enclose the head and body of a patient, and means for alternately increasing and reducing pressure on the body of said patient, said means including an electric motor drive, a magnetic clutch for transmittingpower therefrom, and clutch control means including a source of electric current, a circuit including a switch leading from said source to said clutch; and means responsive to expansion and contraction of said body during breathing for opening said switch at a predetermined point in the breathing of said patient.

6. In a respirometer comprising a casing, adapted to enclose the head and body of a patient. means for alternately increasing and reducing pressure on said body to increase breathing action thereof, said means including an electric motor drive, a magnetic clutch for transmitting power therefrom, and clutch control means including a source of electric current, a circuit therefrom to said clutch, said circuit including a switch; and means responsive to breathing of said patient for opening said switch at a predetermined point in the breathing of said patient.

7. In a respirometer including a scalable head chamber, pumping mechanisms respectively for into said chamber, and actuating means for said mechanisms,- a passageway adapted to permit flow from said chamber to said withdrawing mechanism, means for preventing return flow through said passageway, an expansible and collapsible air repository, a second passageway leading from said withdrawing mechanism to said repository, means for preventing return flow to said withdrawing mechanism, a third passageway leading from said second passageway into said introduction mechanism, means for preventing return flow therethrough, an additional passageway for permitting flow from said introduction mechanism into said chamber, means for preventing return flow from said chamber through the last said passageway, and means for opening said return flow-preventing means, between said chamber and said introducing mechanism, concurrently with completion of each introduction and each withdrawing movement.

8. In a 'respirometer including a sealable head chamber, pumping mechanism respectively for withdrawing air from and for introducing air into said chamber, and actuating means for said mechanisms, a passageway adapted to permit said withdrawing mechanism, a third passageway leading from said second passageway into said introduction mechanism, means for preventing return flow therethrough, an additional passageway for permitting flow fromsaid introduction mechanism into said chamber, means for preventing return flow from said chamber through the last said passageway, and cooperative means for temporarily establishing direct flow between said chamber and said repository concurrently with completion of each air introduction and each air withdrawal.

CHARLES M. HAMMOND. 

